#pragma once
#ifndef BZF_MD5_H
#define BZF_MD5_H

#include <string>
#include <cstring>
#include <iostream>

// a small class for calculating MD5 hashes of strings or byte arrays
// it is not meant to be fast or secure
//
// usage: 1) feed it blocks of uchars with update()
//      2) finalize()
//      3) get hexdigest() string
//      or
//      MD5(std::string).hexdigest()
//
// assumes that char is 8 bit and int is 32 bit
namespace cores
{
    namespace common
    {
		class MD5
		{
		public:
			typedef unsigned int size_type; // must be 32bit

			MD5();
			MD5(const std::string &text);
			void update(const unsigned char *buf, size_type length);
			void update(const char *buf, size_type length);
			MD5 &finalize();
			std::string hexdigest() const;
			friend std::ostream &operator<<(std::ostream &, MD5 md5);

		private:
			void init();
			typedef unsigned char uint1; //  8bit
			typedef unsigned int uint4;	 // 32bit
			enum
			{
				blocksize = 64
			}; // VC6 won't eat a const static int here

			void transform(const uint1 block[blocksize]);
			static void decode(uint4 output[], const uint1 input[], size_type len);
			static void encode(uint1 output[], const uint4 input[], size_type len);

			bool finalized;
			uint1 buffer[blocksize]; // bytes that didn't fit in last 64 byte chunk
			uint4 count[2];			 // 64bit counter for number of bits (lo, hi)
			uint4 state[4];			 // digest so far
			uint1 digest[16];		 // the result

			// low level logic operations
			static inline uint4 F(uint4 x, uint4 y, uint4 z);
			static inline uint4 G(uint4 x, uint4 y, uint4 z);
			static inline uint4 H(uint4 x, uint4 y, uint4 z);
			static inline uint4 I(uint4 x, uint4 y, uint4 z);
			static inline uint4 rotate_left(uint4 x, int n);
			static inline void FF(uint4 &a, uint4 b, uint4 c, uint4 d, uint4 x, uint4 s, uint4 ac);
			static inline void GG(uint4 &a, uint4 b, uint4 c, uint4 d, uint4 x, uint4 s, uint4 ac);
			static inline void HH(uint4 &a, uint4 b, uint4 c, uint4 d, uint4 x, uint4 s, uint4 ac);
			static inline void II(uint4 &a, uint4 b, uint4 c, uint4 d, uint4 x, uint4 s, uint4 ac);
		};

		std::string md5(const std::string str);
	}
}

#endif